Mesenchymal stem cells alleviate idiopathic pneumonia syndrome by modulating T cell function through CCR2-CCL2 axis

Diffuse Alveolar Hemorrhage in Hematopoietic Cell Transplantation

Diffuse alveolar hemorrhage (DAH) is a morbid syndrome that occurs after autologous and allogeneic hematopoietic cell transplantation in children and adults. DAH manifests most often in the first few weeks following transplantation. It presents with pneumonia-like symptoms and acute respiratory failure, often requiring high levels of oxygen supplementation or mechanical ventilatory support. Hemoptysis is variably present. Chest radiographs typically feature widespread alveolar filling, sometimes with peripheral sparing and pleural effusions. The diagnosis is suspected when serial bronchoalveolar lavages return increasingly bloody fluid. DAH is differentiated from infectious causes of alveolar hemorrhage when extensive microbiological testing reveals no pulmonary pathogens. The cause is poorly understood, though preclinical and clinical studies implicate pretransplant conditioning regimens, particularly those using high doses of total-body-irradiation, acute graft-versus-host disease (GVHD), medications used to prevent GVHD, and other factors. Treatment consists of supportive care, systemic corticosteroids, platelet transfusions, and sometimes includes antifibrinolytic drugs and topical procoagulant factors. Therapeutic blockade of tumor necrosis factor-α showed promise in observational studies, but its benefit for DAH remains uncertain after small clinical trials. Even with these treatments, mortality from progression and relapse is high. Future investigational therapies could target the vascular endothelial cell biology theorized to contribute to alveolar bleeding and pathways that contribute to susceptibility, inflammation, cellular resilience, and tissue repair. This review will help clinicians navigate through the limited evidence to diagnose and treat DAH, counsel patients and families, and plan for future research.

Successful treatment with mesenchymal stem cells for steroid-refractory late-onset idiopathic pneumonia syndrome following allogeneic hematopoietic cell transplantation

The reportedly poor outcome of late-onset idiopathic pneumonia syndrome (IPS) necessitates new approaches to its treatment. A 55-year-old man who had undergone allogeneic hematopoietic cell transplantation (allo-HCT) for myelodysplastic syndrome 1 year ago developed dyspnea with acute skin graft-versus-host disease (GVHD) flare-up while tapering immunosuppressive agents. He presented with acute respiratory distress syndrome with ground-glass opacities in the right upper and left lower lobes. All infectious tests, including multiplex polymerase chain reaction of nasal wash, were negative, and broad-spectrum antibiotic therapy was refractory. The patient was diagnosed with late-onset IPS and was refractory to methylprednisolone pulse therapy. He then showed a favorable response to mesenchymal stem cell (MSC) infusion. After eight infusions of MSCs, he had no IPS recurrence for over one year. Recently, preclinical studies have reported the potential therapeutic utility of MSC infusion for treating IPS, and our case supports its potential for treating late-onset IPS.

Mesenchymal stem cell-based therapy for paraquat-induced lung injury

Paraquat poisoning results in significant pulmonary damage, but current treatments are only minimally effective in repairing the injured lung tissues. Recent research has highlighted the promise of using stem cell therapy, namely mesenchymal stem cells, as a new method for treating paraquat toxicity. These cells have shown effectiveness in decreasing inflammation, apoptosis, and fibrosis in the mice lungs subjected to paraquat. The therapeutic implications of mesenchymal stem cells are believed to arise from their release of bioactive proteins and their capacity to regulate inflammatory responses. However, additional clinical study is required to validate these therapies' efficacy. This review thoroughly explores the pathophysiology of paraquat poisoning and the properties of mesenchymal stem cells. Additionally, it critically assesses the long-term safety and effectiveness of mesenchymal stem cell therapies, which is crucial for developing more dependable and effective treatment protocols. In summary, although mesenchymal stem cells offer promising prospects for treating lung injuries, more investigations are required to optimize their therapeutic promise and ensure their safe clinical application in the context of paraquat poisoning.

Superior migration ability of umbilical cord-derived mesenchymal stromal cells (MSCs) toward activated lymphocytes in comparison with those of bone marrow and adipose-derived MSCs

Introduction: Mesenchymal stromal cells (MSCs) are activated upon inflammation and/or tissue damage and migrate to suppress inflammation and repair tissues. Migration is the first important step for MSCs to become functional; however, the migration potency of umbilical cord-derived MSCs (UC-MSCs) remains poorly understood. Thus, we aimed to assess the migration potency of UC-MSCs in comparison with those of bone marrow-derived MSCs (BM-MSCs) and adipose tissue-derived MSCs (AD-MSCs) and investigate the influence of chemotactic factors on the migration of these cells. Methods: We compared the migration potencies of UC-, BM-, and AD-MSCs toward allogeneic stimulated mononuclear cells (MNCs) in mixed lymphocyte reaction (MLR). The number of MSCs in the upper chamber that migrated toward the MLR in the lower chamber was counted using transwell migration assay. Results and discussion: UC-MSCs showed significantly faster and higher proliferation potencies and higher migration potency toward unstimulated MNCs and MLR than BM- and AD-MSCs, although the migration potencies of the three types of MSCs were comparable when cultured in the presence of fetal bovine serum. The amounts of CCL2, CCL7, and CXCL2 in the supernatants were significantly higher in UC-MSCs co-cultured with MLR than in MLR alone and in BM- and AD-MSCs co-cultured with MLR, although they did not induce the autologous migration of UC-MSCs. The amount of CCL8 was higher in BM- and AD-MSCs than in UC-MSCs, and the amount of IP-10 was higher in AD-MSCs co-cultured with MLR than in UC- and BM-MSCs. The migration of UC-MSCs toward the MLR was partially attenuated by platelet-derived growth factor, insulin-like growth factor 1, and matrix metalloproteinase inhibitors in a dose-dependent manner. Conclusion: UC-MSCs showed faster proliferation and higher migration potency toward activated or non-activated lymphocytes than BM- and AD-MSCs. The functional chemotactic factors may vary among MSCs derived from different tissue sources, although the roles of specific chemokines in the different sources of MSCs remain to be resolved.

Study on Potential Differentially Expressed Genes in Idiopathic Pulmonary Fibrosis by Bioinformatics and Next-Generation Sequencing Data Analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with reduced quality of life and earlier mortality, but its pathogenesis and key genes are still unclear. In this investigation, bioinformatics was used to deeply analyze the pathogenesis of IPF and related key genes, so as to investigate the potential molecular pathogenesis of IPF and provide guidance for clinical treatment. Next-generation sequencing dataset GSE213001 was obtained from Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) were identified between IPF and normal control group. The DEGs between IPF and normal control group were screened with the DESeq2 package of R language. The Gene Ontology (GO) and REACTOME pathway enrichment analyses of the DEGs were performed. Using the g:Profiler, the function and pathway enrichment analyses of DEGs were performed. Then, a protein-protein interaction (PPI) network was constructed via the Integrated Interactions Database (IID) database. Cytoscape with Network Analyzer was used to identify the hub genes. miRNet and NetworkAnalyst databaseswereused to construct the targeted microRNAs (miRNAs), transcription factors (TFs), and small drug molecules. Finally, receiver operating characteristic (ROC) curve analysis was used to validate the hub genes. A total of 958 DEGs were screened out in this study, including 479 up regulated genes and 479 down regulated genes. Most of the DEGs were significantly enriched in response to stimulus, GPCR ligand binding, microtubule-based process, and defective GALNT3 causes HFTC. In combination with the results of the PPI network, miRNA-hub gene regulatory network and TF-hub gene regulatory network, hub genes including LRRK2, BMI1, EBP, MNDA, KBTBD7, KRT15, OTX1, TEKT4, SPAG8, and EFHC2 were selected. Cyclothiazide and rotigotinethe are predicted small drug molecules for IPF treatment. Our findings will contribute to identification of potential biomarkers and novel strategies for the treatment of IPF, and provide a novel strategy for clinical therapy.

Noninfectious Pulmonary Complications after Hematopoietic Stem Cell Transplantation

Pulmonary complications after hematopoietic stem cell transplantation (HSCT) are important sources of morbidity and mortality. Improvements in infection-related complications have made noninfectious pulmonary complications an increasingly significant driver of transplantation-related mortality. Broadly, these complications can be characterized as either early or late complications, with idiopathic pneumonia syndrome and bronchiolitis obliterans syndrome the most prevalent early and late complications, respectively. Outcomes with historical treatment consisting mainly of corticosteroids are often poor, highlighting the need for a deeper understanding of these complications' underlying disease biology to guide the adoption of novel therapies that are being increasingly used in the modern era.

Mesenchymal stem cell homing to improve therapeutic efficacy in liver disease

Mesenchymal stem cell (MSC) transplantation, as an alternative strategy to orthotopic liver transplantation, has been evaluated for treating end-stage liver disease. Although the therapeutic mechanism of MSC transplantation remains unclear, accumulating evidence has demonstrated that MSCs can regenerate tissues and self-renew to repair the liver through differentiation into hepatocyte-like cells, immune regulation, and anti-fibrotic mechanisms. Multiple clinical trials have confirmed that MSC transplantation restores liver function and alleviates liver damage. A sufficient number of MSCs must be home to the target tissues after administration for successful application. However, inefficient homing of MSCs after systemic administration is a major limitation in MSC therapy. Here, we review the mechanisms and clinical application status of MSCs in the treatment of liver disease and comprehensively summarize the molecular mechanisms of MSC homing, and various strategies for promoting MSC homing to improve the treatment of liver disease.

JEV Infection Induces M-MDSC Differentiation Into CD3+ Macrophages in the Brain

Japanese encephalitis virus (JEV) is one of the most important members of the flavivirus family. It is a typical zoonotic pathogen that has caused substantial social and economic losses worldwide. The relation between JEV-induced immunosuppression and inflammatory responses has not been thoroughly investigated. In this study, cells infiltrating the brain tissue of JEV-infected mice were mainly identified as monocytic myeloid-derived suppressor cells (M-MDSCs), which subsequently differentiated into CD3⁺ macrophages. Co-culture with T cells showed that both splenic M-MDSCs and brain infiltrated M-MDSCs isolated from JEV-infected mice inhibited T cell proliferation through ARG1 and iNOS. The splenectomy model revealed that JEV-induced M-MDSCs were mainly derived from bone marrow and migrated to the spleen and central nervous system (CNS). The results of the transcriptome analysis and IRF7-deficient mice indicated that the ZBP1-IRF7 signaling pathway stimulated by JEV RNA played a central role in the induction of M-MDSCs. M-MDSCs migrated into the CNS through the chemokine CCL2/N-CCL2 derived from astrocytes and brain infiltrated M-MDSCs differentiated into CD3⁺ macrophages through a mechanism mediated by M-CSF, IL-6 and IFN-γ in the brain microenvironment. These findings provide evidence for the mechanism that JEV regulates the differentiation of M-MDSCs and thereby exacerbates pathogenicity, which represents a potential therapeutic target for Japanese encephalitis (JE).

Mesenchymal stem cell treatment for COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has caused a global pandemic since late 2019 that resulted in more than 360 million population infection. Among them, less than 7% of infected individuals develop severe or critical illness. Mass vaccination has been carried out, but reinfection and vaccine breakthrough cases still occur. Besides supportive and antiviral medications, much attention has been paid in immunotherapies that aim at reducing pathological changes in the lungs. Mesenchymal stem cells (MSCs) is used as an option because of their immunomodulatory, anti-inflammatory, and regenerative properties. As of January 16, 2022, when ClinicalTrials.gov was searched for "Mesenchymal stem cells and COVID-19," over 80 clinical trials were registered. MSC therapy was found to be safe and some effective in preclinical and clinical studies. Here, we summarize the major pathological characteristics of COVID-19 and provide scientific and rational evidence for the safety and possible effectiveness of MSCs in COVID-19 treatment.